1. Field of the Invention
The present invention relates generally to the use of N-{2-[3-chloro-5-(trifluoromethyl)-2-pridinyl]ethyl}-2-(trifluoromethyl)benzamide(fluopyram) for controlling nematodes in nematode resistant crops and to methods particularly useful for controlling nematodes and/or increasing crop yield in those crops.
2. Description of Related Art
Fluopyram is defined to be the compound of the formula (I)
as well as the N-oxides of the compound thereof.
Fluopyram is a broad spectrum fungicide with penetrant and translaminar properties for foliar, drip, drench and seed treatment applications on a wide range of different crops against many economically important plant diseases. It is very effective in preventative applications against powdery mildew species, grey mould and white mould species. It has an efficacy against many other plant diseases. Fluopyram has shown activity in spore germination, germ tube elongation and mycelium growth tests. At the biochemical level, fluopyram inhibits mitochondrial respiration by blocking the electron transport in the respiratory chain of Succinate Dehydrogenase (complex II-SDH inhibitor).
Fluopyram and its manufacturing process starting from known and commercially available compounds is described in EP-A-1 389 614 and WO 2004/016088.
A general description of the nematicidal activity of pyridylethylbenzamide derivatives is found in WO-A 2008/126922.
Nematodes are tiny, worm-like, multicellular animals adapted to living in water. The number of nematode species is estimated at half a million. An important part of the soil fauna, nematodes live in a maze of interconnected channels, called pores, that are formed by soil processes. They move in the films of water that cling to soil particles. Plant-parasitic nematodes, a majority of which are root feeders, are found in association with most plants. Some are endoparasitic, living and feeding within the tissue of the roots, tubers, buds, seeds, etc. Others are ectoparasitic, feeding externally through plant walls. A single endoparasitic nematode can kill a plant or reduce its productivity. Endoparasitic root feeders include such economically important pests as the root-knot nematodes (Meloidogyne species), the reniform nematodes (Rotylenchulus species), the cyst nematodes (Heterodera species), and the root-lesion nematodes (Pratylenchus species). Direct feeding by nematodes can drastically decrease a plant's uptake of nutrients and water. Nematodes have the greatest impact on crop productivity when they attack the roots of seedlings immediately after seed germination. Nematode feeding also creates open wounds that provide entry to a wide variety of plant-pathogenic fungi and bacteria. These microbial infections are often more economically damaging than the direct effects of nematode feeding.
Generally nematode resistance is characterized by host plant cell death at or nearby the feeding site of the parasitic nematode. Particular resistance genes and nematode interaction influence the timing and localization of the resistance response. Williamson et al. (Trends in Genetics, Vol. 22, No. 7, July 2006) describes the nature and mechanisms of plant-nematode interactions with respect to resistance in plants.
Nematode-resistant plants can be related to three main approaches being nematode targets, nematode-crop interface and plant response. Antifeedant or nematicidal proteins, disruption of essential nematode gene expression by RNA interference, disruption of sensory function by RNA interference, peptides or plantibodies or nematicidal metabolites are examples for nematode targets; disruption of nematode pathogenicity factors regarding migration and invasion or regarding feeding site induction and maintenance by RNA interference, peptides or plantibodies, stealth or repellant plants; or the conversion of host plants to non-host plants are examples for nematode-crop interface while plant resistance gene or hypersensitive response activation by nematode invasion; Induced cell death or other site incompatibility by feeding site specific promoters or conversion of crops to tolerance are examples for plant response.
Although nematode-resistant plants are described to be resistant towards specific nematodes, there is still some interactions between the nematode and the crop which, due to the different defense reactions of the plant, might lead to a partially impaired plant. One example of these defense reactions is the hypersensitive response. One consequence might result in impaired roots and loss of vigor of the affected plants.
Current nematode control focuses essentially on the prevention of nematode attack on the plant. Once a plant is parasitized it is virtually impossible to kill the nematode without also destroying the plant. Therefore, it would be advantageous to provide enhanced nematode control compounds and methods of treating nematode resistant plants to prevent or reduce nematode damage.
A large part of the damage to crop plants which is caused by pests occurs as early as when the seed is attacked during storage and after the seed is introduced into the soil, during and immediately after germination of the plants. This phase is particularly critical since the roots and shoots of the growing plant are particularly sensitive and even minor damage can lead to the death of the whole plant. Thus, it is desirable to develop methods for protecting the seed and the germinating plant which dispense with the additional application of crop protection agents after sowing or after the emergence of the plants. It is furthermore desirable to optimize the amount of active compound employed in such a way as to provide maximum protection for the seed and the germinating plant from attack by pests, but without damaging the plant itself by the active compound employed. In particular, methods for the treatment of seed should also take into consideration the intrinsic insecticidal properties of transgenic plants in order to achieve optimum protection of the seed and also the germinating plant with a minimum of crop protection agents being employed.